Medical conditions sometimes require the replacement or support of a damaged tissue or structure. Such replacement or support can be made via the use of fillers, either temporarily or permanently. Exemplary applications of such filler compositions include sutures and surgical nets that have been used for organ support in spleen, liver, and kidney repair procedures. A non-immunogenic, bioerodible, implantable composition with alginate fibers is known, as is a biological tissue transplant coated with a stabilized multi-layer alginate. Transplantable artificial pancreatic tissue can be prepared from an alginic acid gel precursor, a matrix monomer, and pancreas cells with Ca2+ ions and a matrix monomer polymerization catalyst. The calcium-alginic acid composition is used to provide mechanical integrity to the mixture while the matrix monomer is polymerized, after which the calcium-alginic acid composition is removed to leave a porous matrix. The calcium-alginic acid composition functions as a processing aid not as a structural member in the final artificial device. Also, alginate fibers have been used in preparation of wound dressings.
Formation of fibers with ionically crosslinked alginates requires contacting crosslinking agents, such as the cation of choice, with the alginate of choice. While contacting a crosslinking agent with an alginate generally is not considered difficult, controlling the formation and termination of the alginate fibers has been difficult. The difficulty arises from the rapidity in which alginate crosslinks once exposed to crosslinking ions. Controlling fiber formation and fiber termination is a major problem of existing preparation methods that employ the simple mixing of the two agents.